The present invention relates generally to decks and, more particularly, to a deck plank that has a tongue and a groove.
Wood is commonly used for decks. However, the use of wood for decks presents a number of problems. First, constant exposure to the elements can cause the wood to deteriorate over time. In order to prevent (or delay) this from happening, the wood must be treated with a wood preservative. Treating the wood can be a time consuming and messy process. Next, wood is frequently stained or painted to achieve a desired color, but the color can fade, chip, and peel over time.
In addition, the dimensions of wood vary depending on the moisture content of the wood and the temperature. These variations can cause warping of the boards which can cause the surface of the deck to become uneven over time. Finally, when a tongue and groove arrangement of boards is used, if the head of the nail is not flush with the surface of the board, the next board will not fit against it properly, resulting in an uneven surface.
Synthetic wood compositions have been advanced as a substitute for natural wood. Synthetic wood compositions may offer improved durability and enhanced moisture resistance over natural wood. Nevertheless, synthetic wood compositions may still expand and contract as a result of temperature and moisture variations. Consequently, a deck made from synthetic wood deck planks may also become uneven due to expansion and contraction of the synthetic wood material.
Therefore, it would be desirable to have an improved tongue and groove joint. It would also be desirable to have a deck plank having improved dimensional stability and decreased maintenance. The deck plank should be easy to install. The design of the deck plank should ensure that the deck will be smooth and even when installed. In particular, the tongue and groove of the deck plank should compensate for expansion and contraction of the material of the deck plank.
The present invention satisfies some or all of these needs. The present invention provides a deck plank that is preferably comprised of a wood replacement material. The deck plank has a tongue that includes a sacrificial limb. The sacrificial limb is adapted to fracture, if necessary, in response to expansion of the material of the deck plank to limit vertical displacement of the top surface of the deck plank. The present invention also provides a deck and a method of making a deck.
A preferred embodiment of a deck plank of the present invention includes a top surface, a first leg, and a second leg. The top surface may be substantially flat and horizontal. The top surface has a first end portion and a second end portion. The first leg is attached to the first end portion, and the second leg is attached to the second end portion. The first leg and the second leg may form at least one open area beneath the top surface. The first leg extends downward from the top surface, and it has a tongue and an outer surface. The tongue has a first limb and a second limb which are joined together to define a recess that preferably extends the length of the deck plank. The outer surface defines a channel that extends along the tongue. The channel preferably extends the length of the tongue. The second leg also extends downward from the top surface, and it has an upper portion and a lower portion. The upper portion and the lower portion define a groove, and the tongue is adapted to fit with a groove of an adjacent, substantially similar deck plank. When the tongue of the deck plank is placed in the groove of an adjacent deck plank, the channel of the deck plank is adapted to induce one of the limbs to fracture, if necessary, in response to expansion of the material of the deck plank so that vertical displacement of the top surface is limited.
Many different shapes for the first leg and groove design may be used, including curves and various complex shapes. The first leg and the second leg of the deck plank are preferably adapted to maintain a gap between a portion of the first leg of the deck plank and a portion of the second leg of an adjacent deck plank when an outer portion of the tongue of the deck plank is placed adjacent to an inner portion of the groove of the adjacent deck plank. For example, the first leg may have an angled portion of a first angle and the second leg may have an angled portion of a second angle. The first angle may be sufficiently different from the second angle such that the first leg and the second leg are adapted to maintain a gap between the angled portion of the first leg of the deck plank and the angled portion of the second leg of the adjacent deck plank when an outer portion of the tongue of the deck plank is placed adjacent to an inner portion of the groove of the adjacent deck plank. The first angle may be greater or less than the second angle. It is preferred that the outer portion of the tongue and the inner portion of the groove are substantially vertical.
In addition, the first leg may have an upper portion above the tongue, and the second leg may have an upper portion above the groove. The upper portion of the first leg and the upper portion of the second leg may be adapted to maintain a gap between the upper portion of the first leg of the deck plank and the upper portion of the second leg of an adjacent deck plank when an outer portion of the tongue of the deck plank is placed adjacent to an inner portion of the groove of the adjacent deck plank.
The deck plank may include at least one other leg attached to and extending downward from the top surface at a point intermediate between the first and second end portions. The top surface of the deck plank may include a channel extending the length of the deck plank to provide an escape path for water that comes into contact with the top surface. The tongue may include a vertical cutout that preferably allows water to escape through a joint between adjacent deck planks.
A deck plank may be attached to a support structure with at least one fastener such as a nail. A fastener preferably extends through the lower portion of the second leg of the deck plank. Those skilled in the art should also recognize that a deck plank of the present invention may be installed by other conventional means such as screws, bolts, and adhesives.
The deck plank may be made from wood, plastics, or from several other materials including conventional wood replacement materials such as synthetic wood compositions. However, it is believed that the present invention is unique apart from material considerations. The wood replacement material may be comprised of a polymer, such as homopolymers and copolymers of polyethylene, polyvinyl chloride, polypropylene and ABS, or a mixture of these polymers. The wood replacement material also preferably includes cellulose material for appearance, stiffness, and economics. The cellulose material may be in the form of fibers (e.g., wood flour and the like). Table 1 shows an example formulation of a wood replacement material. The deck planks made from wood replacement materials are preferably extruded using conventional plastics extrusion equipment and one or more dies to provide the desired cross section shape of each plank.
TABLE 1 ______________________________________ Wood Flour 50% (by weight) HDPE 45% (by weight) Zinc Stearate 2.5% (by weight) Wax 2.5% (by weight) ______________________________________
The present invention also includes a deck. The deck may include a support structure and at least one deck plank. The at least one deck plank is attached to the support structure. The deck also preferably includes a starter strip that is attached to the support structure. The starter strip may be made from a wood replacement material. The starter strip may have a groove that is adapted to receive the tongue of the deck plank.
The starter strip may have a leg that defines a groove. The leg of the starter strip may be shaped so that a gap is maintained between a portion of the first leg of the deck plank and a portion of the leg of the starter strip when an outer portion of the tongue of the deck plank is placed adjacent to an inner portion of the groove of the starter strip. For example, the leg of the starter strip may have an angled portion of a third angle. The first angle of a deck plank may be sufficiently different from the third angle of the starter strip so that a gap is maintained between the angled portion of the first leg of the deck plank and the angled portion of the starter strip when an outer portion of the tongue of the deck plank is placed adjacent to an inner portion of the groove of the starter strip. The first angle of the deck plank may be greater or less than the third angle of the starter strip.
The present invention also includes a method of making a deck. A preferred method includes providing a support structure, providing a first deck plank, and attaching the first deck plank to the support structure. The method may further include providing a second deck plank, placing the tongue of the second deck plank adjacent to the groove of the first deck plank, and attaching the second deck plank to the support structure. In such an embodiment, a channel of the second deck plank is adapted to induce one of the limbs of the second deck plank to fracture, if necessary, in response to expansion of the material of the deck planks so that vertical displacement of the top surface of the second deck plank is limited.
Another method of the present invention includes providing a support structure, providing a starter strip, attaching the starter strip to the support structure, providing a first deck plank, placing the tongue of the first deck plank adjacent to the groove of the starter strip, and attaching the first deck plank to the support structure.
In addition to the novel features and advantages mentioned above, other objects and advantages of the present invention will be readily apparent from the following descriptions of the drawings and preferred embodiments.